In wallboard construction, the joint between adjacent sheets of wallboard is usually covered by a paper tape extending lengthwise along the joint. The conventional drywall tape is provided in narrow elongated strips of porous paper wound into rolls. The drywall tape is applied to the joints, and then covered with wet plaster or “mud”. The plaster is feathered and smoothed along the edges of the tape to conceal the tape edges and form a smooth unmarred surface where the wallboard adjoins.
It is often necessary to cut the wallboard to form a corner, which thereby exposes the plaster contained between the heavy paper sheets. This exposed plaster tends to crumble unless these edges are protected. To finish exterior corners in wallboard construction, metal corner beads are typically installed. Such corner beads are conventionally formed by rollforming from an elongated strip of sheet metal, and provide a rounded nose with two mounting flanges extending at substantially right angles from the opposing sides of the nose. These mounting flanges often provide a rough surface so that the joint compound will adhere when the corner is finished.
The corner bead is installed by securing the mounting flanges along the surface of the drywall panels adjacent to the corner by nails or the like. Additionally, such flanges may be covered with a tape which is affixed to the wallboard by mud or wet plaster which is smoothed into place to cover the flanges, or flanges and tape.
The finished exterior corners, in wallboard construction, covered with a radiused or arcuate metal corner bead is transitioned, near the floor, from the rounded corner to a 90 degree corner. The drywall 90 degree corner is formed to accommodate carpenters in applying trim at the bottom of drywall and against the floor. The 90 degree corner, at the bottom of the corner, allows the carpenter to perform normal mitering of wood or composites which are used in base molding products. Transition corners typically provide a curved portion mating with the radiused or arcuate metal corner above the floor area and are secured in place by nails or staples through flanges extending on each leg of the approximate 90 degree angle corner. The transition corner is first placed by the workman near the floor and over or under the radiused or arcuate corner with a vertical placement intended by the workman. Invariably the securing of the transition corner, via nails or other such mechanical means, causes a lateral force moving the transition corner away from the vertical. The workman must repeatedly remove securing nails or staples and reposition the transition corner until a vertical placement has been achieved. Such labor intensive effort increases the expense of installing wallboard.
U.S. Pat. No. 6,295,776 to Kunz et al discloses and claims a manufacturing process for a tape-on type corner bead, having an elongated metal core strip with a longitudinal arcuate nose and a pair of flanges extending outwardly from the nose where each flange is covered by a strip of paper bonded to the exterior surface which also comprise wings which project outwardly beyond the extent of the flanges. The paper cover strip is dimensionally stable on contact with wet joint compound. There is no transition from round to right angle demonstrated. U.S. Pat. Pub. No. 2003/0131546 to Kunz discloses and claims the apparatus disclosed in U.S. Pat. No. 6,295,776. U.S. Pat. No. 6,539,680 to Kunz discloses and claims the bead of the apparatus disclosed in U.S. Pat. No. 6,295,776. U.S. Pat. No. 5,138,810 to Kartler discloses a corneraide. U.S. Pat. No. 4,313,991 to Lamb discloses a seam taping member having a bead. U.S. Pat. No. 4,719,732 to Bernard discloses a covering over the 90 degree corner of wallboard which rounds the corner to a small radius. There is no transition from round to right angle disclosed.
The patents referred to herein are provided herewith in an Information Disclosure Statement in accordance with 37 CFR 1.97.